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1.
J Fish Dis ; 40(3): 293-310, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27334576

RESUMO

Megalocytiviruses cause high mortality diseases that have seriously impacted aquaculture, with the most frequent outbreaks occurring in East and South-East Asia. The international trade of juvenile fish for food and ornamental aquaculture has aided the spread of these viruses, which have spread to Europe and Australia and other regions. Australian freshwater fishes were examined for susceptibility to infection with the exotic megalocytivirus, dwarf gourami iridovirus (DGIV), which belongs to a group with the type species, Infectious spleen and kidney necrosis virus (ISKNV). Fish were held at 23 ± 1 °C and challenged by intraperitoneal (IP) injection or by cohabitation with Murray cod, Maccullochella peelii (Mitchell) infected with DGIV. A species was deemed to be susceptible to DGIV based on evidence of viral replication, as determined by qPCR, and megalocytic inclusion bodies observed histologically. Horizontal transmission occurred between infected Murray cod and golden perch, Macquaria ambigua (Richardson), Macquarie perch, Macquaria australasica (Cuvier) and Murray cod. This indicated that DGIV shed from infected fish held at 23 °C can survive in fresh water and subsequently infect these naïve fish. Further, DGIV administered IP was highly pathogenic to golden perch, Macquarie perch and Murray cod. Compared to these species, the susceptibility of southern pygmy perch, Nannoperca australis (Gunther) was lower. Freshwater catfish (dewfish), Tandanus tandanus (Mitchell), were not susceptible under the experimental conditions based on the absence of clinical disease, mortality and virus replication. This study showed the potential risks associated with naïve and DGIV-infected fish sharing a common water source.


Assuntos
Peixes-Gato , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/transmissão , Iridoviridae/fisiologia , Perciformes , Animais , Austrália , Infecções por Vírus de DNA/transmissão , Infecções por Vírus de DNA/virologia , Suscetibilidade a Doenças/veterinária , Suscetibilidade a Doenças/virologia , Doenças dos Peixes/virologia , Água Doce
2.
Dis Aquat Organ ; 122(2): 105-123, 2016 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-28000602

RESUMO

Although infections caused by megalocytiviruses have been reported from a wide range of finfish species for several decades, molecular characterisation of the viruses involved has been undertaken only on more recent cases. Sequence analysis of the major capsid protein and adenosine triphosphatase genes is reported here from formalin-fixed, paraffin-embedded material from 2 archival ornamental fish cases from 1986 and 1988 in conjunction with data for a range of genes from fresh frozen tissues from 5 cases obtained from 1991 through to 2010. Turbot reddish body iridovirus (TRBIV) genotype megalocytiviruses, previously not documented in ornamental fish, were detected in samples from 1986, 1988 and 1991. In contrast, megalocytiviruses from 1996 onwards, including those characterised from 2002, 2006 and 2010 in this study, were almost indistinguishable from infectious spleen and kidney necrosis virus (ISKNV). Three of the species infected with TRBIV-like megalocytiviruses from 1986 to 1991, viz. dwarf gourami Trichogaster lalius (formerly Colisa lalia), freshwater angelfish Pterophyllum scalare and oscar Astronotus ocellatus, were infected with ISKNV genotype megalocytiviruses from 2002 to 2010. The detection of a TRBIV genotype isolate in ornamental fish from 1986 represents the index case, confirmed by molecular sequence data, for the genus Megalocytivirus.


Assuntos
Peixes/virologia , Iridoviridae/genética , Iridoviridae/isolamento & purificação , Animais , Bancos de Espécimes Biológicos , DNA Viral/genética , DNA Viral/isolamento & purificação , Genótipo , Filogenia
3.
Lancet Neurol ; 7(1): 25; author reply 25, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18093557
4.
Proc Natl Acad Sci U S A ; 97(24): 13442-7, 2000 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-11078512

RESUMO

The African trypanosome, Trypanosoma brucei, has been shown to undergo genetic exchange in the laboratory, but controversy exists as to the role of genetic exchange in natural populations. Much of the analysis to date has been derived from isoenzyme or randomly amplified polymorphic DNA data with parasite material from a range of hosts and geographical locations. These markers fail to distinguish between the human infective (T. b. rhodesiense) and nonhuman infective (T. b. brucei) "subspecies" so that parasites derived from hosts other than humans potentially contain both subspecies. To overcome some of the inherent problems with the use of such markers and diverse populations, we have analyzed a well-defined population from a discrete geographical location (Busoga, Uganda) using three recently described minisatellite markers. The parasites were primarily isolated from humans and cattle with the latter isolates further characterized by their ability to resist lysis by human serum (equivalent to human infectivity). The minisatellite markers show high levels of polymorphism, and from the data obtained we conclude that T. b. rhodesiense is genetically isolated from T. b. brucei and can be unambiguously identified by its multilocus genotype. Analysis of the genotype frequencies in the separated T. b. brucei and T. b. rhodesiense populations shows the former has an epidemic population structure whereas the latter is clonal. This finding suggests that the strong linkage disequilibrium observed in previous analyses, where human and nonhuman infective trypanosomes were not distinguished, results from the treatment of two genetically isolated populations as a single population.


Assuntos
DNA de Protozoário/genética , Repetições Minissatélites , Trypanosoma brucei brucei/genética , Trypanosoma brucei rhodesiense/genética , Animais , Bovinos , Genótipo , Geografia , Humanos , Epidemiologia Molecular , Trypanosoma brucei brucei/isolamento & purificação , Trypanosoma brucei rhodesiense/isolamento & purificação , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/parasitologia , Tripanossomíase Bovina/epidemiologia , Tripanossomíase Bovina/parasitologia , Uganda , Zâmbia
6.
Mol Hum Reprod ; 5(9): 809-15, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10460218

RESUMO

Human semen contains a large amount of alpha-L-fucosidase activity, the great majority of which is found in the seminal fluid. Immunocytochemical studies indicate that a small amount of semen fucosidase activity is present on the sperm plasma membrane, primarily in the posterior head region. Subcellular fractionation studies also indicate that sperm alpha-L-fucosidase is present in the plasma membrane-enriched fraction. Comparative characterization of human seminal fluid and sperm alpha-L-fucosidases indicates that seminal fluid alpha-L-fucosidase has a broad pH optimum curve with a number of near-equal maxima between pH 4.8 and 7.0 while sperm fucosidase has a major optimum between pH 3.4 and 4.0. Isoelectric focusing indicates that seminal fluid alpha-L-fucosidase contains three to six isoforms with isoelectric points (pI) of 5-7 while sperm fucosidase contains two distinct isoforms with pI values of 5. 2 +/- 0.2 and 7.0 +/- 0.2. Western blotting indicates that seminal fluid fucosidase contains a major protein band with a molecular mass ratio (M(r)) of approximately 56 kDa while sperm fucosidase contains a major protein band of approximately 51 kDa. The overall results indicate the presence of a low-abundance, plasma membrane-associated human sperm alpha-L-fucosidase, which is different in its properties from human seminal fluid alpha-L-fucosidase(s), and whose function is not yet known.


Assuntos
Sêmen/enzimologia , Espermatozoides/enzimologia , alfa-L-Fucosidase/análise , Western Blotting , Membrana Celular/enzimologia , Estabilidade Enzimática , Humanos , Concentração de Íons de Hidrogênio , Imuno-Histoquímica , Focalização Isoelétrica , Isoenzimas/metabolismo , Cinética , Masculino , Valores de Referência , Espermatozoides/citologia , Frações Subcelulares
8.
Med Lab Technol ; 30(2): 183-5, 1973 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-4750000
11.
J Med Lab Technol ; 26(2): 152-3, 1969 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-5785365
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